Physical Sciences and Mathematics Commons^™

Factors Influencing Student Outcomes In A Large, Online Simulation-Based Introductory Statistics Course, Ella M. Burnham

Department of Statistics: Dissertations, Theses, and Student Work

The demand for statistical knowledge and skills is growing in many disciplines, so more students are enrolling in introductory statistics courses (Blair, Kirkman, & Maxwell, 2018). At the same time, institutions are seeking course delivery methods that allow for greater flexibility for students, especially following the onset of the COVID-19 pandemic; therefore, there is more interest in the development and delivery of online introductory statistics courses.

To address this, I collaboratively designed an online introductory statistics course which focuses on simulation-based inference for the University of Nebraska-Lincoln. The course design was informed by the Community of Inquiry framework (Garrison, Anderson, …

Avian Influenza A Virus Susceptibility, Infection, Transmission, And Antibody Kinetics In European Starlings, Jeremy W. Ellis, J. Jeffrey Root, Loredana M. Mccurdy, Kevin T. Bentler, Nicole L. Barrett, Kaci K. Vandalen, Katherine L. Dirsmith, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

Avian influenza A viruses (IAVs) pose risks to public, agricultural, and wildlife health. Bridge hosts are spillover hosts that share habitat with both maintenance hosts (e.g., mallards) and target hosts (e.g., poultry). We conducted a comprehensive assessment of European starlings (Sturnus vulgaris), a common visitor to both urban and agricultural environments, to assess whether this species might act as a potential maintenance or bridge host for IAVs. First, we experimentally inoculated starlings with a wild bird IAV to investigate susceptibility and replication kinetics. Next, we evaluated whether IAV might spill over to starlings from sharing resources with a …

Voltage-Controlled Magnetization In Chromia-Based Magnetic Heterostructures, William Echtenkamp

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Spintronics promises a new generation of low-power, high-speed, non-volatile memory and logic devices. Heterostructures based on magnetoelectric chromia enable the direct manipulation of magnetization by applied electric fields and emerged as a promising building block for spintronic devices. In this dissertation, several interesting emergent magnetic properties arising in these device-enabling building blocks are examined. In some cases, exchange coupling at the interface between the magnetoelectric antiferromagnet and an adjacent ferromagnet stabilizes the interfacial antiferromagnetic domain state against the electrically induced rotation of the bulk spin structure. Upon magnetically cycling the ferromagnet, the magnetoelectric antiferromagnet relaxes towards a commensurate spin structure …

Results On Nonorientable Surfaces For Knots And 2-Knots, Vincent Longo

Department of Mathematics: Dissertations, Theses, and Student Research

A classical knot is a smooth embedding of the circle into the 3-sphere. We can also consider embeddings of arbitrary surfaces (possibly nonorientable) into a 4-manifold, called knotted surfaces. In this thesis, we give an introduction to some of the basics of the studies of classical knots and knotted surfaces, then present some results about nonorientable surfaces bounded by classical knots and embeddings of nonorientable knotted surfaces. First, we generalize a result of Satoh about connected sums of projective planes and twist spun knots. Specifically, we will show that for any odd natural n, the connected sum of the n-twist …

Mesopredator Frugivory Has No Effect On Seed Viability And Emergence Under Experimental Conditions, John P. Draper, Trisha B. Atwood, Noelle G. Beckman, Karin M. Kettenring, Julie K. Young

United States Department of Agriculture Wildlife Services: Staff Publications

Members of the order Carnivora are a unique and important seed disperser who consume and deposit undamaged seeds while providing regular long-distance seed dispersal opportunities. Some members of Carnivora, such as coyotes (Canis latrans), are undergoing range expansions which may help the plant species they consume colonize new locations or replace dispersal services provided by recently extirpated species. In this study, we evaluated aspects of the seed dispersal effectiveness of coyotes and gut passage time to determine the potential dispersal distances for three commonly consumed and commonly occurring plant species (Amelanchier alnifolia, Celtis ehrenbergiana, and Juniperus osteosperma). We also investigated …

Nicarbazin As An Oral Contraceptive In Eared Doves, Lourdes Olivera, Silvia Pereyra, Georgget Banchero, Guillermo Tellechea, Jorge Sawchik, Michael L. Avery, Ethel Rodríguez

United States Department of Agriculture Wildlife Services: Staff Publications

Eared doves (Zenaida auriculata) are responsible for substantial losses in cereal and oil crops as well as in dairy and feedlot production in the southern cone of South America. Various strategies have been shown to be effective in reducing damage at the farm scale, but in some scenarios, it is necessary to also incorporate population control methods due to excessive bird population size. An alternative approach to reduce pest bird populations is the use of contraceptive methods, minimizing the impact on the environment and non-target populations. Nicarbazin is registered in the United States as a contraceptive for Branta …

Manipulation Of Spin Crossover Phenomenon In An Fe (Ii) Molecular Complex And Application To Molecular Spintronics, Guanhua Hao

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Molecules with a large local magnetic moment have attracted considerable attention for application in spintronic devices. One candidate of a suitable device goes to the spin crossover molecule, where these 3d transition metal compounds are able to exhibit a robust spin state transition between distinct states. By proper design, the spintronic devices fabricated via spin crossover molecular thin films could achieve novel functionality while retaining flexibility and other traits based on its “organic” nature.

Controlling the spin state transition is a key factor of these possibilities. This thesis work investigates the manipulation of the spin state transition in [Fe{H …

The Design, Creation, And Cognitive Evaluation Of Ranking Tasks In Introductory Astronomy, Emily A. Welch

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Ranking tasks are a type of interactive formative assessment. They allow students to explore a concept by ranking similar situations for a specified variable, preferably without computation of that variable. I created two sets of introductory astronomy ranking tasks: the first connects the Hertzsprung–Russell (HR) diagram and the Stephan-Boltzmann luminosity equation; the second uses the transit method (TM) to rank exoplanets by comparing the depth, duration, and frequency of transits.

These tasks are designed within the constructivist pedagogical framework. They require students to call upon their own relevant schema to establish an assessment rule by which to rank the tasks. …

Free Complexes Over The Exterior Algebra With Small Homology, Erica Hopkins

Department of Mathematics: Dissertations, Theses, and Student Research

Let M be a graded module over a standard graded polynomial ring S. The Total Rank Conjecture by Avramov-Buchweitz predicts the total Betti number of M should be at least the total Betti number of the residue field. Walker proved this is indeed true in a large number of cases. One could then try to push this result further by generalizing this conjecture to finite free complexes which is known as the Generalized Total Rank Conjecture. However, Iyengar and Walker constructed examples to show this generalized conjecture is not always true.

In this thesis, we investigate other counterexamples of …

A Real-World, Hybrid Event Sequence Generation Framework For Android Apps, Jun Sun

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Generating meaningful inputs for Android apps is still a challenging issue that needs more research. Past research efforts have shown that random test generation is still an effective means to exercise User-Interface (UI) events to achieve high code coverage. At the same time, heuristic search approaches can effectively reach specified code targets. Our investigation shows that these approaches alone are insufficient to generate inputs that can exercise specific code locations in complex Android applications.

This thesis introduces a hybrid approach that combines two different input generation techniques--heuristic search based on genetic algorithm and random instigation of UI events, to reach …

Using Contextual Bandits To Improve Traffic Performance In Edge Network, Aziza Al Zadjali

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Edge computing network is a great candidate to reduce latency and enhance performance of the Internet. The flexibility afforded by Edge computing to handle data creates exciting range of possibilities. However, Edge servers have some limitations since Edge computing process and analyze partial sets of information. It is challenging to allocate computing and network resources rationally to satisfy the requirement of mobile devices under uncertain wireless network, and meet the constraints of datacenter servers too. To combat these issues, this dissertation proposes smart multi armed bandit algorithms that decide the appropriate connection setup for multiple network access technologies on the …

Aerial Flight Paths For Communication, Alisha Bevins

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

This body of work presents an iterative process of refinement to understand naive perception of communication using the motion of an unmanned aerial vehicle (UAV). This includes what people believe the UAV is trying to communicate, and how they expect to respond through physical action or emotional response. Previous work in this area sought to communicate without clear definitions of the states attempting to be conveyed. In an attempt to present more concrete states and better understand specific motion perception, this work goes through multiple iterations of state elicitation and label assignment. The lessons learned in this work will be …

Bootstrap Percolation On Random Geometric Graphs, Alyssa Whittemore

Department of Mathematics: Dissertations, Theses, and Student Research

Bootstrap Percolation is a discrete-time process that models the spread of information or disease across the vertex set of a graph. We consider the following version of this process:

Initially, each vertex of the graph is set active with probability p or inactive otherwise. Then, at each time step, every inactive vertex with at least k active neighbors becomes active. Active vertices will always remain active. The process ends when it reaches a stationary state. If all the vertices eventually become active, then we say we achieve percolation.

This process has been widely studied on many families of graphs, deterministic …

Application Of Artificial Intelligence And Machine Learning In Libraries: A Systematic Review, Rajesh Kumar Das, Mohammad Sharif Ul Islam

Library Philosophy and Practice (e-journal)

As the concept and implementation of cutting-edge technologies like artificial intelligence and machine learning has become relevant, academics, researchers and information professionals involve research in this area. The objective of this systematic literature review is to provide a synthesis of empirical studies exploring application of artificial intelligence and machine learning in libraries. To achieve the objectives of the study, a systematic literature review was conducted based on the original guidelines proposed by Kitchenham et al. (2009). Data was collected from Web of Science, Scopus, LISA and LISTA databases. Following the rigorous/ established selection process, a total of thirty-two articles were …

A Typology Of Drought Decision Making: Synthesizing Across Cases To Understand Drought Preparedness And Response Actions, Amanda E. Cravens, Jen Henderson, Jack Friedman, Nina Burkardt, Ashley E. Cooper, Tonya Haigh, Michael Hayes, Jamie Mcenvoy, Stephanie Paladino, Adam K. Wilke, Hailey Wilmer

Drought Mitigation Center: Faculty Publications

Drought is an inescapable reality in many regions, including much of the western United States. With climate change, droughts are predicted to intensify and occur more frequently, making the imperative for drought management even greater. Many diverse actors – including private landowners, business owners, scientists, non-governmental organizations (NGOs), and managers and policymakers within tribal, local, state, and federal government agencies – play multiple, often overlapping roles in preparing for and responding to drought. Managing water is, of course, one of the most important roles that humans play in both mitigating and responding to droughts; but, focusing only on “water managers” …

Super Solar, William Wilton

Honors Expanded Learning Clubs

No abstract provided.

Integrated Geophysical Analysis Over Bathymetrists Seamounts And The Sierra Leone Rise, Alexa Fernandez

UCARE Research Products

The Bathymetrists Seamounts (BSM) are located northeast of the Sierra Leone Rise in the Atlantic Ocean. The northern seamounts have a southwest to northeast trend which is contrary to the current eastward motion of the African tectonic plate where they reside. The geological history and crustal structures of these features are poorly understood. The goal of this study is to integrate multiple geophysical data to better understand the crustal architecture and tectonic history of the BSM.

The seismic refraction study from Jones et al. (2015) was used as the baseline for isostatic modeling. This dataset suggested the presence of magmatic …

Spatiotemporal Trends In Bacterial Diversity Across Three Watersheds Within The Platte River Basin, Nebraska, Esther Perisho

School of Natural Resources: Dissertations, Theses, and Student Research

River bacteria are understudied despite being critical components of river ecosystems. There are even fewer studies considering bacteria communities at large spatiotemporal scales, which may provide insight into drivers of community assembly. We investigated differences in bacterial diversity across environmental gradients within three sub-basins nested in the Platte River Basin, Nebraska. Surface water samples were collected weekly at 36 sites from May to September by the Nebraska Department of Environment and Energy (NDEE) in 2019. Bacterial communities were sequenced using the Illumina MiSeq platform. Sub-basins had similar counts of unique amplicon sequence variants (ASVs) but different community structures. These structural …

Right Side Up: Payment For Ecosystem Services On Privately Owned Grasslands In Nebraska, Kyle Martens

School of Natural Resources: Dissertations, Theses, and Student Research

Grasslands are an important ecological and economic resource in the United States. As part of a natural system, these landscapes can provide income for ranching operations and employment in rural communities; habitat for grassland plants, animals, and migratory species; and offer other services not always readily observed such as improved soil health, clean water, and carbon sequestration. Despite the overarching benefits, the conversion of grasslands to other uses remains widespread throughout much of the remaining Great Plains ecosystem.

Shifting from livestock ranching to another land use often reflects a tipping point. This occurs when the alternative land use is perceived …

Biomaterials With Structural Hierarchy And Controlled 3d Nanotopography Guide Endogenous Bone Regeneration, Shixuan Chen, Hongjun Wang, Valerio Luca Mainardi, Giuseppe Talò, Alec Mccarthy, Johnson V. John, Matthew J. Teusink, Liu Hong, Jingwei Xie

Chemistry Department: Faculty Publications

Biomaterials without exogenous cells or therapeutic agents often fail to achieve rapid endogenous bone regeneration with high quality. Here, we reported a class of three-dimensional (3D) nanofiber scaffolds with hierarchical structure and controlled alignment for effective endogenous cranial bone regeneration. 3D scaffolds consisting of radially aligned nanofibers guided and promoted the migration of bone marrow stem cells from the surrounding region to the center in vitro. These scaffolds showed the highest new bone volume, surface coverage, and mineral density among the tested groups in vivo. The regenerated bone exhibited a radially aligned fashion, closely recapitulating the scaffold’s architecture. The organic …

Developing A Database Of Seismic Data Over The Cascadia Subduction Zone, Khawlh Al Farsi

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

An inevitable megathrust earthquake is expected in the Cascadia subduction zone that will affect the population of the coast of southwestern British Columbia and the northwest of the United States. In this active tectonic margin, the Juan de Fuca oceanic plate is subducting beneath the North American continental plate, causing unevenly distributed seismic activity. The major goal of this geophysical research project is to study the tectonic structures of the Cascadia subduction zone in order to comprehend the geology of the region and investigate the seismic hazards. The primary objective of this project is to develop a geophysical database of …

Atomic Photoionization By Multiple Temporal Pairs Of Slits, Jean Marcel Ngoko Djiokap

Department of Physics and Astronomy: Faculty Publications

We study interactions between multiple temporal pairs of slits in coherent control of photoionization of S-state atoms using a pulse train of N + 1 pairs evenly delayed in time by τ , in which the two pulses in a pair with a delay τ₀ are counter-rotating circularly polarized. For interacting two double-slit experiments, while Ramsey interference between two identical Archimedean spirals yields pairs of principal spirals, interference of two spirals with opposite handedness does not lead to spirals, but instead to crocodile-eye-like patterns with nictares. For more than two interacting experiments, the resulting patterns turn out just to …

U.S. Geological Survey Science For The Wyoming Landscape Conservation Initiative—2018 Annual Report, Patrick J. Anderson, Cameron L. Aldridge, Jason S. Alexander, Timothy J.` Assal, Steven Aulenbach, Zachary H. Bowen, Anna D. Chalfoun, Geneva W. Chong, Holly Copeland, David R. Edmunds, Steve Germaine, Tabitha Graves, Julie A. Heinrichs, Collin G. Homer, Christopher G. Huber, Aaron N. Johnston, Matthew J. Kauffman, Daniel J. Manier, Ryan R. Mcshane, Cheryl A. Eddy-Miller, Kirk A. Miller, Adrian P. Monroe, Michael S. O'Donnell, Anna Ortega, Annika W. Walters, Daniel J. Wieferich, Teal B. Wyckoff, Linda Zeigenfuss

United States Geological Survey: Water Reports and Publications

The Wyoming Landscape Conservation Initiative (WLCI) was established in 2007 as a collaborative interagency partnership to develop and implement science-based conservation actions. During the past 11 years, partners from U.S. Geological Survey (USGS), State and Federal land management agencies, universities, and the public have collaborated to implement a long-term (more than 10 years) science-based program that assesses and enhances the quality and quantity of wildlife habitats in the southwest Wyoming region while facilitating responsible development. The USGS WLCI Science Team completes scientific research and develops tools that inform and support WLCI partner planning, decision making, and on-the-ground management actions.

In …

Dynamical Variations Of The Global Covid-19 Pandemic Based On A Seicr Disease Model: A New Approach Of Yi Hua Jie Mu, Xia Wang, Gang Yin, Zengyun Hu, Daihai He, Qianqian Cui, Xiaomei Feng, Zhidong Teng, Qi Hu, Jiansen Li, Qiming Zhou

Department of Earth and Atmospheric Sciences: Faculty Publications

The ongoing coronavirus disease 2019 (COVID-19) pandemic has caused more than 150 million cases of infection to date and poses a serious threat to global public health. In this study, global COVID-19 data were used to examine the dynamical variations from the perspectives of immunity and contact of 84 countries across the five climate regions: tropical, arid, temperate, and cold. A new approach named Yi Hua Jie Mu is proposed to obtain the transmission rates based on the COVID-19 data between the countries with the same climate region over the Northern Hemisphere and Southern Hemisphere. Our results suggest that the …

Near-Optimal Learning Of Tree-Structured Distributions By Chow-Liu, Arnab Bhattacharyya, Sutanu Gayen, Eric Price, N. V. Vinodchandran

Department of Mathematics: Faculty Publications

We provide finite sample guarantees for the classical Chow-Liu algorithm (IEEE Trans. Inform. Theory, 1968) to learn a tree-structured graphical model of a distribution. For a distribution P on Σⁿ and a tree T on n nodes, we say T is an ε-approximate tree for P if there is a T-structured distribution Q such that D(P || Q) is at most ε more than the best possible tree-structured distribution for P. We show that if P itself is tree-structured, then the Chow-Liu algorithm with the plug-in estimator for mutual information with eO (|Σ| …

Developing Pandemic Comics For Youth Audiences, Judy Diamond, Amy Spiegel, Patricia Wonch Hill, Elizabeth Vanwormer, Judi M. Gaiashkibos, Bob Hall, Aaron Sutherlen, Julia Mcquillan

University of Nebraska State Museum: Staff and Affiliates, Publications

In spring 2020 our team received funding from the Rapid Response Research program of the National Science Foundation to develop comics that would help youth understand the COVID-19 pandemic. Our project built on a decade of expertise creating comics about the biology of viruses. In collaboration with virologists and artists, we developed three comic stories about COVID-19 during the pandemic and posted them on-line during the last half of 2020. The fictional narratives address fundamental issues in biology, virology, and network science, in order to help readers understand the complexities of living through a viral pandemic. The stories focus on …

Aromatic Substitution: Another View, Charles A. Kingsbury

Chemistry Department: Faculty Publications

Electrophilic substitution on substituted benzenes is reviewed in terms of molecular orbitals. The HOMO falls into two classes. For all meta director C-X groups, a node passes through the ring and through the substituent C-X bond. With ortho/para director C-X groups, a node perpendicular to the one described above, passes through the ortho-meta bonds.

Downscaling Of Far-Red Solar-Induced Chlorophyll Fluorescence Of Different Crops From Canopy To Leaf Level Using A Diurnal Data Set Acquired By The Airborne Imaging Spectrometer Hyplant, Bastian Siegmann, Maria Pilar Cendrero-Mateo, Sergio Cogliati, Alexander Damm, John Gamon, David Herrera, Christopehr Jedmowski, Laura Verena Junker-Frohn, Thorsten Kraska, Onno Muller, Patrick Rademske, Christiaan Van Der Tol, Juan Quiros-Vargas, Peiqi Yang, Uwe Rascher

School of Natural Resources: Faculty Publications

Remote sensing-based measurements of solar-induced chlorophyll fluorescence (SIF) are useful for assessing plant functioning at different spatial and temporal scales. SIF is the most direct measure of photosynthesis and is therefore considered important to advance capacity for the monitoring of gross primary production (GPP) while it has also been suggested that its yield facilitates the early detection of vegetation stress. However, due to the influence of different confounding effects, the apparent SIF signal measured at canopy level differs from the fluorescence emitted at leaf level, which makes its physiological interpretation challenging. One of these effects is the scattering of SIF …

The Future Of Wildlife Conservation Funding: What Options Do U.S. College Students Support?, Lincoln R. Larson, Markus Nils Peterson, Richard Von Furstenberg, Victoria R. Vayer, Kangjae Jerry Lee, Daniel Y. Choi, Kathryn Stevenson, Adam A. Ahlers, Christine Anhalt-Depies, Taniya Bethke, Jeremy T. Bruskotter, Christopher J. Chizinski, Brian Clark, Ashley A. Dayer, Kelly Heber Dunning, Benjamin Ghasemi, Larry Gigliotti, Alan Graefe, Kris Irwin, Samuel J. Keith, Matt Kelly, Gerard Kyle, Elizabeth Metcalf, Wayde Morse, Mark D. Needham, Neelam C. Poudyal, Michael Quartuch, Shari Rodriguez, Chelsie Romulo, Ryan L. Sharp, William Siemer, Matthew T. Springer, Brett Stayton, Richard Stedman, Taylor Stein, Timothy R. Van Deelen, Jason Whiting, Richelle L. Winkler, Kyle Maurice Woosnam

School of Natural Resources: Faculty Publications

Insufficient funding is a major impediment to conservation efforts around the world. In the United States, a decline in hunting participation threatens sustainability of the “user-pay, public benefit” model that has supported wildlife conservation for nearly 100 years, forcing wildlife management agencies to contemplate alternative funding strategies. We investigated support for potential funding options among diverse college students, a rapidly expanding and politically active voting bloc with a potentially powerful influence on the future of conservation. From 2018 to 2020, we surveyed 17,203 undergraduate students at public universities across 22 states. Students preferred innovative approaches to conservation funding, with 72% …

Effect Of Correlated Oxide Electrodes On Disorder Pinning And Thermal Roughening Of Ferroelectric Domain Walls In Epitaxial Pbzr0.2Ti0.8O3 Thin Films, Kun Wang, Yifei Hao, Le Zhang, Yuanyuan Zhang, Xuegang Chen, Xia Hong

Department of Physics and Astronomy: Faculty Publications

We report the competing effects of disorder pinning and thermal roughening on ferroelectric domain walls as a function of temperature in epitaxial PbZr_0.2Ti_0.8O₃ thin films deposited on (001) SrTiO₃ substrates buffered by three types of correlated oxide electrodes, La_0.67Sr_0.33MnO₃, LaNiO₃, and SrIrO₃. Piezoresponse force microscopy studies show that the 50-nm PbZr_0.2Ti_0.8O₃ films are uniformly polarized in the as-grown states, with the patterned domain structures persisting above 700 °C. For all three types of films, the domain wall roughness is …